Microsoft essentially have 2 editions of a program. The first edition speaks English (User Interface) to the user, but in behind can speak French (COM) to other components.
The second edition also speaks English and French, but can also speak Russian (VSIP - Visual Studio Integration Programme).
Microsoft intends that your components speak Russian in order to extend Visual Studio. Their VSIP license agreement also states that you can only try to speak Russian to the second edition of the software. Attempting to speak Russian to the first edition is not allowed (even if it does speak the language).
Rather than try and speak Russian, Jamie has been using French. He has asked Visual Studio if it talks a certain dialect (COM interface), and it has said "oui". So he uses that dialect to talk to Visual Studio in order to do what he needs.
The main problem from Microsoft's point of view is that they didn't intend for anyone to use that dialect of French in order to talk to Visual Studio. They only expected Russian to be used. However, there's nothing that explicitly states this. Microsoft even has public notes on the French dialect.
Therefore, Jamie thinks he's in the right because Microsoft have not said that speaking French is forbidden. Microsoft sees it the other way. And the way things are going, it looks like the decision is going to come from a judge or jury.